Connector insulator



D. E. KRUP CONNECTOR INSULATOR Dec. 9, 1969 2 Sheets-Sheet 1 Filed April23, 1958 Dec. 9, 1969 D. E. KRUP 3,483,310

CONNECTOR INSULATOR Filed April 23, 1968 2 Sheets-Sheet 2 United StatesPatent O US. Cl. 174-87 8 Claims ABSTRACT OF THE DISCLOSURE A connectorassembly for joining the stripped ends of insulated electrical wiresincluding a sleeve to fit over and be fastened to the ends of the wiresand a connector cap of flexible insulating material having a sleeveretaining member. The sleeve retaining member is made of a tough,elastic plastic. It is tubular in shape and has an outer cylindricalportion which seats in the connector cap and an inner frusto-conicalportion which spreads when the sleeve is forced into the cap andcontracts to engage the sleeve to prevent it from being readily removedfrom the cap.

SUMMARY OF THE INVENTION This invention is concerned with a connectorassembly for joining the stripped ends of insulated electrical wires andmore particularly with a connector assembly in which wires held togetherby a sleeve are pushed into locking engagement with a connector cap.

An object of this invention is a connector assembly in which theconnector cap is made of a flexible plastic material.

Another object is a connector assembly in which all of the components ofthe connector cap are electrically nonconductive.

Another object is a retaining member for a connector cap which is madeof a tough, elastic plastic.

Another object is a connector cap which can be easily assembled.

Another object is a connector cap which permits easy insertion of wiresand sleeve into the cap but resists pull out of the wires and sleeve.

Another object is a connector cap which is reusable, at least to alimited extent.

Other objects may be found in the following specification, claims anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated more orless diagrammatically in the following drawings wherein:

FIGURE 1 is a plan view of the connector assembly showing the connectorcap and wires before insertion of the wires into the cap;

FIGURE 2 is a cross-sectional view through a crimped portion of thesleeve of FIGURE 1;

FIGURE 3 is an enlarged longitudinal cross-section view of the connectorcap of FIGURE 1 showing the sleeve and wires being inserted through theretaining member and showing the fully connected position of the wiresand sleeve in phantom;

FIGURE 4 is a view taken along the line 44 of FIG- URE 3 with the sleeveretaining member, sleeve, and Wires omitted for clarity;

FIGURE 5 is an end elevational view of a sleeve retaining member ofFIGURE 3;

FIGURE 6 is a view taken along line 6-6 of FIG- URE 5;

FIGURE 7 is a side elevational view of the sleeve retaining member ofFIGURE 3;

FIGURE 8 is an end elevational view of a modified form of sleeveretaining member; and

FIGURE 9 is a view taken along line 99 of FIG- URE 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The connector assembly, shownin FIGURE 1, includes a connector shell or cap 11 and a sleeve 13 withthe sleeve adapted to fit over and contain the stripped ends ofinsulated wires 14. The sleeve 13 has a cylindrical portion 15 and abell-shaped flange portion 16. The shall or cap 11 may be molded of aflexible plastic having high dielectric characteristics, such as areexhibited by the thermoplastic materials, and is formed with a centralbore 17 extending therethrough as seen in FIGURE 3; One end of the boreis closed by a wall 19 and the other end has an opening 21. Inwardly ofthe opening 21, the bore is tapered at 23 to a throat 25 of reducedcross-section. A portion 27 of the bore, located inwardly of the throat,is formed with a cross section larger than that of the throat butsmaller than that of the main portion of the bore 17. An annular channelor groove 29 is formed in the portion 27 of the bore. A plurality oflongitudinally extending, inwardly projecting and circumferentiallyspaced ribs 31 are formed in the annular channel 29 (FIG. 4). Ribs 32may also be formed on the exterior of the cap 11 to facilitate handlingand use thereof.

A sleeve retaining member 35, shown separately in FIGURES 5, 6, and 7,is seated in the annular channel 29 in the manner shown in FIGURE 3. Thechannel is slightly longer than the retaining member for ease ofassembly of the retaining member with the cap. Longitudinal movement ofthe sleeve retaining member relative to the bore is limited byengagement of the member with the end walls of channel 29. The sleeveretaining member, which is molded of a tough, elastic plastic such asnylon, is tubular in shape and includes an outer cylindrical portion 37and an inner frusto-conical portion 39. The inner portion 39 iscantileverly attached to one end 41 of the outer cylindrical portion.The opening 43 of the smaller end of the frusto-conical inner portion 39is located between the openings 45 and 57 at opposite ends of the sleeveretaining memebr 35.

The sleeve retaining member 35 is split by a longitudinally extendingslot 49, most clearly shown in FIGURE 5. Another longitudinallyextending slot 51 is formed in the outer cylindrical portion 37 at alocation spaced approximately 180 from the slot 49. The slot 51 extendsless than the length of the outer cylindrical portion to form a hinge 52adjacent the cantilever connection of the inner and outer portions.Grooves 53, which mate with the ribs 31 formed in the channel 29 of theshell 11, are formed in the outer surface of the outer cylindricalportion 37 of the retaining member to prevent rotation of the sleeveretaining member when it is positioned in the cap.

A modified form of sleeve retaining member 61 is shown in FIGURES 8 and9. This member has an outer cylindrical portion 63 and an innerfrusto-conical portion 65 cantileverly attached to one end 67 of theouter cylindrical portion. The member 61 is split by a slot 69 extendinglongitudinally therethrough and the outer cylindrical portion 63 isslotted at 71 longitudinally for a distance less than its length to forma hinge 72 similar to hinge 52. It should be noted that the notch 71 isnot located diametrically opposite to slot 69. The free and smaller end73 of the inner frusto-conical member 65 is notched at 74 and 75 todivide this end into three segments. A gusset or web 77 is provided toextend between each one of these segments and the outer cylindricalportion 63 to function as reinforcements. The gussets or webs 77 extendnon-radially as shown in FIGURE 8. Grooves 79 are formed in the outersurface of the outer cylindrical portion 63 to mate with the ribs 31 ofthe channel 29 of the cap 11 to prevent rotation of the sleeve retainingmember relative to the cap.

The spacings between the ends 43 and 73 of the frustoconical portions ofthe retaining member and the end wall 19 of the cap are suflicient topermit the sleeve 13 to fit therebetween with its flange 16 inwardlythereof.

The use, operation, and function of this invention are as follows:

In using a connector assembly of the type shown herein, the insulationis stripped from the ends of the wires 14 and these ends are placedalongside one another. A sleeve 13 is slipped over the ends of the wiresand is forced into engagement with and secured to the wires by means ofa crimping tool. One or two crimps may be needed to secure the sleeve tothe wires. After the sleeve is secured to the wires, the free end of thewires extending beyond the sleeve may be cut off adjacent the end of thesleeve.

The crimping operation changes the cross-sectional shapes of both thecylindrical portion 15 of the sleeve 13 and the bell-shaped flange 16from the circular shapes shown in FIGURE 1 to the triangular orkidney-shapes shown in FIGURE 2. The maximum transverse dimension of theerimped sleeve generally is greater than the inside diameter of theopening 43 of the inner frusto-conical portion 39 of the sleeveretaining member 35. Therefore, when the wires and attached sleeve areinserted into the sleeve retaining member located in the bore 17 of theconnector cap 11, the cylindrical portion 15 of the sleeve 13 willengage the inner frusto-conical portion 39 of the retaining member andspread this portion outwardly as seen in FIGURE 3. Additional spreadingof the frustoconical portion 39 occurs when the flange 16 is forcedthrough the opening 43 thereof. Expansion or spreading of the innerportion 39 of the sleeve retaining member is facilitated by theprovision of the slots 49 and 51 and the hinge 52 of the outercylindrical portion. When the modified sleeve retaining member 61 isused, the spreading of the inner frusto-conical portion 65 is aided bythe slots 73 and 75 in this portion in addition to the spreadingafforded by the slots 69 and 71 and hinge 72 of the outer cylindricalportion. The non-radial positioning of the gussets 77 permit them toflex or flatten against the outer cylinder portion 63 when thefrusto-conical portion is spread thus presenting minimum resistance tothis spreading.

When the sleeve 13 is inserted to its fully seated position (shown inphantom in FIGURE 3), the inner frustoconical portion of the retainingmember will snap back to its position shown in FIGURE 6 and will contactthe flange 16 of the sleeve 13 to resist disengagement of the sleeve andwires from the cap 11. When the modified form 61 of retaining member isused, reverse bending of the inner frusto-conical portion 65 is alsoresisted by the webs or gussets 77.

Although both forms of retaining member shown in this application willresist disengagement or pullout of the sleeve and Wires from theconnector cap at least to an extent sufiicient to meet the standards setby organizations such as the Underwriters Laboratories, Inc., theseretaining members will permit pullout upon the application of forcesbeyond a predetermined amount without causing serious permanent damageto the retaining member. Therefore, the connector assembly of thisinvention is reusable, at least to a limited extent. However, continuousconnection and removal of the sleeve and wires relative to the retainingmember will ultimately cause permanent damage to the retaining memberand render the connector assembly unsuitable for further use.Modification of the connector so that it cannot be reused may beaccomplished by forming the retaining member of a material stiffer andslightly more brittle than the nylon suggested in this application. Thesubstitute material should be such that it will be destroyed orpermanently deformed upon removal of the sleeve and Wires so that theconnector assembly cannot be reused.

The slots 49 and 69 and the hinge portions 52 and 72 of the retainingmember 35 and 61 respectively permit limited compression of theretaining member. This design facilitates installation of the retainingmember in the cap 11.

The provision of a relatively long outer cylindrical portion (37, 63) onthe sleeve retaining member and a relatively wide channel 29 forreceiving this outer cylindrical portion permits the retention of thesleeve retaining member in a connector cap such as cap 11 which is madeof a flexible plastic. A sleeve retainer having a relatively short outercylindrical portion in engagement with the cap might not remain inposition in a flexible cap.

What is claimed is:

1. An insulating connector for receiving and covering the ends of aplurality of electrical wires held together by a sleeve,

a shell of flexible insulating material having a generally central boreopen at one end and enclosed at the other end by a Wall,

a sleeve retaining member of axially elongated tubular shape and havinga length greater than its thickness and positioned in said bore andspaced from the ends of the bore with said retaining member limited inlongitudinal movement in the bore,

said sleeve retaining member having an annular generally cylindricalouter portion and an annular generally frusto-conical inner portioncantileverly connected to said outer portion with said retaining memberpositioned in said bore so that said inner portion converges towardssaid end wall,

said inner portion having a minimum inner diameter smaller than theouter dimension of said sleeve,

means to permit said inner portion to expand so that a sleeve and wiresmay be moved through said sleeve retaining member into said bore and toallow such inner portion to contact said sleeve to resist removal ofsaid sleeve and wires from said bore,

said free end of said inner portion being spaced from said end wall ofthe shell a suflicient distance to permit said sleeve to be positionedin said bore inwardly of said free end.

2. The structure of claim 1 further characterized in that said sleeveretaining member is made of a tough elastic plastic.

3. The structure of claim 1 further characterized in that said means topermit said inner portion to expand to permit a sleeve and wires to bemoved therethrough includes a longitudinal interruption formed in thecylindrical outer and frusto-conical portions of the tubular retainingmember.

4. The structure of claim 3 further characterized in that alongitudinally extending notch is formed in said cylindrical outermember at a location approximately away from said longitudinallyextending interruption.

5. The structure of claim 1 further characterized in that a plurality oflongitudinally extending notches are formed in said inner frusto-conicalportion extending from the free end thereof for a distance less than thelength thereof to thereby divide s-aid frusto-conical inner portion intoa number of projections.

6. The structure of claim 5 further characterized in that a reinforcingweb is provided between each of said projections and the outercylindrical member.

7. The structure of claim 6 further characterized in that said webs arealigned non-radially with said retaining member.

8. The structure of claim 1 further characterized in that said sleeveretaining member is made of a brittle material formed and adapted tobreak upon removal of said sleeve and wires from said sleeve retainingmember.

(References on following page) References Cited UNITED STATES PATENTSBadeau.

Ustin 17487 Wolf 174-87 Swanson 174 -87

